Combustor triple liner assembly for gas turbine engines

ABSTRACT

A combustor triple liner assembly includes coaxially aligned and radially spaced cylindrical inner, middle and outer liners forming an inner annular flow-path between the inner and the middle liners, and an outer annular flow-path between the middle and the outer liners. A plurality of inner dividers segments the inner annular flow-path into inner compartments. A plurality of outer dividers segments the outer annular flow-path into outer compartments and the middle liner into middle liner sections corresponding to each outer compartment. Each middle liner section includes a plurality of impingement holes fluidly connecting the outer compartment to one corresponding inner compartment which in turn is fluidly connected to one corresponding downstream outer compartment through an opening in the middle liner, such that cooling air flows from the outer compartment through the impingement holes into the corresponding inner compartment and therefrom through the opening into the corresponding downstream outer compartment.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of European Application No.EP17181053 filed 12 Jul. 2017, incorporated by reference herein in itsentirety.

FIELD OF INVENTION

The present invention relates to gas turbines, and more particularly tocombustor assemblies gas turbine engines.

BACKGROUND OF INVENTION

To effectively use cooling air for cooling of gas turbine components isa constant challenge and an important area of interest in gas turbineengine designs. For example, for combustor liner cooling, conventionaldesign uses many impingement holes spread in a large area of a coolingair channel wall or plate, such as a conventional burner plenum surface,overhanging or in close vicinity of the target surface. The cooling airemerges from the impingement holes in form of impingement jets and flowstowards the target surface, for example a combustor liner surface, whichis to be cooled in order to impact the target surface normally. It isimportant to have an adequate velocity in the impingement jets in orderfor the cooling air to reach the target surface and thus to cool thetarget surface. Therefore to achieve adequately high velocity in theimpingement jets, size of the impingement holes is required to be smallbut concentration of impingement holes in a given area is high to ensureadequate volume of the cooling air is available to the target surface.However, since most of the target surfaces, especially combustion linersurface, are longitudinally extended, the impingement jets deliveringthe cooling air to downstream sections of the combustion liner surfaceare subjected to strong cross flow resulting from the cooling air thathas entered through the impingement jets delivering the cooling air toupstream sections of the target surface and then flowing across thelongitudinally extended target surface from the upstream section to thedownstream section of the longitudinally extended target surface.

The cross-flow affects the impingement jets delivering cooling air tothe downstream sections of the combustion liner surface. Thesubstantially normal flow of the cooling air in the impingement jetstowards the target surface is disturbed by the cross flowing cooling airwhich flows substantially parallel to the target surface and as a resultthe impingement jets delivering cooling air to the downstream sectionsof the target surface may not impinge on the target surface especiallyin the downstream sections of the longitudinally extended targetsurface. The disturbance to the impingement jets as a result of thecross flow is increased as the cross flow gains more and more volumefrom the impingement jets received by the cross flow as the cross flowtravels from the upstream section of the target surface to thedownstream section of the target surface. Therefore, an improvement incooling air flow in a combustor is desired.

SUMMARY OF INVENTION

Thus an object of the present technique is to provide a combustorassembly for a gas turbine engine that minimizes the disturbances due tothe cross flow of the cooling air over longitudinally extended targetsurfaces such as a combustor liner surface that are to be cooled byimpingement jets. Another object of the present technique is to reducethe amount of cooling air usage and increase the engine efficiency byre-circulating the cooling air from one flow path to another, and thusmore air is available for combustion.

The above objects are achieved by a combustor triple liner assembly, acombustor assembly, and a gas turbine engine. Advantageous embodimentsof the present technique are provided in dependent claims. Features ofindependent claims may be combined with features of claims dependent onthat independent claim, and features of dependent claims can be combinedtogether.

In a first aspect of the present technique, a combustor triple linerassembly for a gas turbine engine is presented. The combustor tripleliner assembly includes an inner liner, a middle liner, an outer liner,a plurality of inner dividers and a plurality of outer dividers. Theinner liner is a cylinder and has a longitudinal axis. A space definedor contained within the cylindrical inner liner defines a combustionchamber. The middle liner is a cylinder that houses the inner liner. Theouter liner is a cylinder that houses the middle liner. Thus, the innerliner is housed in the middle liner and the middle liner is in turnhoused in the outer liner. The inner liner, the middle liner and theouter liner are coaxially aligned about the longitudinal axis and areradially separated with respect to the longitudinal axis to create aninner annular flow-path between the inner liner and the middle liner,and to create an outer annular flow-path between the middle liner andthe outer liner.

The inner dividers are serially arranged longitudinally within the innerannular flow-path. Each of the inner dividers are annular disc shapedand the radial direction of the disc shaped inner dividers is alignedperpendicular to the longitudinal axis i.e. each inner divider extendsradially about the longitudinal axis between the inner liner and themiddle liner thereby dividing the inner annular flow-path into aplurality of inner compartments.

The outer dividers are serially arranged longitudinally within the outerannular flow-path. Each of the outer dividers are annular disc shapedand the radial direction of the disc shaped outer dividers is alignedperpendicular to the longitudinal axis i.e. each outer divider extendsradially about the longitudinal axis between the middle liner and theouter liner thereby dividing the outer annular flow-path into aplurality of outer compartments. The outer dividers also divide orsegment the middle liner into a plurality of middle liner sectionscorresponding to each outer compartment i.e. each of outer compartmentsincludes a middle liner section.

The middle liner section of each outer compartment includes a pluralityof impingement holes. The impingement holes of each outer compartmentfluidly connect that outer compartment to one corresponding innercompartment and the corresponding inner compartment is fluidly connectedto one corresponding downstream outer compartment through at least oneopening in the middle liner of the downstream outer compartment, suchthat cooling air entering the outer annular flow-path flows from theouter compartment through the impingement holes of the outer compartmentinto the corresponding inner compartment and therefrom through theopening into the corresponding downstream outer compartment.

As an effect of the flow of the cooling air serially flowing through theouter compartment into the corresponding inner compartment through theimpingement holes and then into the corresponding downstream outercompartment and then into the inner compartment corresponding to thecorresponding downstream outer compartment and so on and so forth,buildup of strong cross flow with respect to impingement jets isminimized and thus the impingement jets emanating from the impingementholes of different middle liner sections are able to reach the innerliner and provide effective cooling to the inner liner. Furthermore,sizes of the impingement holes can be controlled individually fordifferent middle liner sections and thus parameters of the impingementjets produced by different middle liner sections, such as velocity ofthe impingement jets, can be controlled and thereby different degrees ofcooling can be achieved locally for different sections of the innerliner. Furthermore, by such recirculation of the cooling air form onecompartment to another one, less cooling air is required and engineefficiency is increased. Furthermore, since the combustor triple linerassembly requires only three parts or components i.e. the inner liner,the middle liner, and the outer liner in addition to the inner and theouter dividers, the construction and assembly of the combustor tripleliner assembly is simple and does not require complicated assembling ofmultiple individual parts.

In an embodiment of the combustor triple liner assembly, the inner linerincludes a plurality of film cooling holes. The film cooling holes allowa part of the cooling air from at least one of the inner compartments,where the film cooling holes are located, to enter the combustionchamber and to provide film cooling of an inner surface of the innerliner. The part of the cooling air flowing into the combustion chamberfrom the inner compartment through the film cooling holes also providescombustion acoustic damping of the inner liner.

In another embodiment of the combustor triple liner assembly, the innerliner includes at least one dilution hole. The dilution holes allows apart of the cooling air from at least one of the inner compartments,where the dilution hole is located, to enter the combustion chamber andthereby dilute the combustion gases in the combustion chamber. The partof the cooling air flowing into the combustion chamber from the innercompartment through the dilution hole mixes with the combustion gas orthe working gas and reduces temperature of the combustion gas.

In another embodiment of the combustor triple liner assembly, theimpingement holes are located in the middle liner section of each outercompartment as an array. The array extends circumferentially and axiallyin the middle liner section and thus impingement jets emanate fromentire area or expanse of the middle liner sections.

In another embodiment of the combustor triple liner assembly, at leastone of the outer dividers includes one or more by-pass holes. Theby-pass holes allow a part of the cooling air to flow from the outercompartment upstream of the outer divider to the outer compartmentdownstream of the outer divider, without flowing through any innercompartment. The part of the cooling air flowing from the upstream outercompartment into the adjacent downstream outer compartment is coolerthan the part of the cooling air flowing into the downstream outercompartment from the inner compartment. This cooler cooling air mixeswith the cooling air flowing into the downstream outer compartment fromthe inner compartment and reduces the temperature of the cooling air inthe downstream outer compartment which then flows into the correspondinginner compartment to cool the inner liner.

In another embodiment of the combustor triple liner assembly, the outerdividers and the inner dividers are integrally formed with the middleliner. Thus the combustor triple liner assembly requires only threeparts or components i.e. the inner liner, the middle liner with theintegrally formed inner and outer dividers, and the outer liner, andtherefore the construction and assembly of the combustor triple linerassembly is simple and does not require complicated assembling ofmultiple individual parts.

In another embodiment of the combustor triple liner assembly, the outerdividers are integrally formed with the middle liner, whereas the innerdividers are integrally formed with the inner liner. Thus, the combustortriple liner assembly requires only three parts or components i.e. theinner liner with the integrally formed inner dividers, the middle linerwith the integrally formed outer dividers, and the outer liner.Therefore the construction and assembly of the combustor triple linerassembly is simple and does not require complicated assembling ofmultiple individual parts.

In another embodiment of the combustor triple liner assembly, the outerdividers are integrally formed with the outer liner, whereas the innerdividers are integrally formed with the middle liner. Thus, thecombustor triple liner assembly requires only three parts or componentsi.e. the inner liner, the middle liner with the integrally formed innerdividers, and the outer liner with the integrally formed outer dividers.Therefore the construction and assembly of the combustor triple linerassembly is simple and does not require complicated assembling ofmultiple individual parts.

In another embodiment of the combustor triple liner assembly, the outerdividers are integrally formed with the outer liner, whereas the innerdividers are integrally formed with the inner liner. Thus, the combustortriple liner assembly requires only three parts or components i.e. theinner liner with the integrally formed inner dividers, the middle liner,and the outer liner with the integrally formed outer dividers. Thereforethe construction and assembly of the combustor triple liner assembly issimple and does not require complicated assembling of multipleindividual parts.

In a second aspect of the present technique, a combustor assembly ispresented. The combustor assembly includes a burner and a combustortriple liner assembly. The combustor triple liner assembly is accordingto the first aspect of the present technique.

In a third aspect of the present technique, a gas turbine engine ispresented. The gas turbine engine includes a combustor triple linerassembly. The combustor triple liner assembly is according to the firstaspect of the present technique.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned attributes and other features and advantages of thepresent technique and the manner of attaining them will become moreapparent and the present technique itself will be better understood byreference to the following description of embodiments of the presenttechnique taken in conjunction with the accompanying drawings, wherein:

FIG. 1 shows part of a gas turbine engine in a sectional view and inwhich an exemplary embodiment of a combustor triple liner assembly ofthe present technique is incorporated;

FIG. 2 schematically illustrates an embodiment of the combustor tripleliner assembly from FIG. 1;

FIG. 3 schematically illustrates a perspective view of anotherembodiment of a section of the combustor triple liner assembly of FIG. 2depicting further structural details of the combustor triple linerassembly;

FIG. 4 schematically illustrates a perspective view of an exemplaryembodiment of a section of an inner liner of the combustor triple linerassembly;

FIG. 5 schematically illustrates a perspective view of another exemplaryembodiment of a section of the inner liner of the combustor triple linerassembly;

FIG. 6 schematically illustrates a perspective view of an exemplaryembodiment of a section of a middle liner of the combustor triple linerassembly;

FIG. 7 schematically illustrates an exemplary scheme of cooling air flowwithin an exemplary embodiment of the combustor triple liner assembly;

FIG. 8 schematically illustrates an exploded view of an exemplaryembodiment of the combustor triple liner assembly;

FIG. 9 schematically illustrates an exploded view of another exemplaryembodiment of the combustor triple liner assembly;

FIG. 10 schematically illustrates an exploded view of yet anotherexemplary embodiment of the combustor triple liner assembly; and

FIG. 11 schematically illustrates an exploded view of a furtherexemplary embodiment of the combustor triple liner assembly; inaccordance with aspects of the present technique.

DETAILED DESCRIPTION OF INVENTION

Hereinafter, above-mentioned and other features of the present techniqueare described in details. Various embodiments are described withreference to the drawing, wherein like reference numerals are used torefer to like elements throughout. In the following description, forpurpose of explanation, numerous specific details are set forth in orderto provide a thorough understanding of one or more embodiments. It maybe noted that the illustrated embodiments are intended to explain, andnot to limit the invention. It may be evident that such embodiments maybe practiced without these specific details.

FIG. 1 shows an example of a gas turbine engine 10 in a sectional view.The gas turbine engine 10 comprises, in flow series, an inlet 12, acompressor or compressor section 14, a combustor section 16 and aturbine section 18 which are generally arranged in flow series andgenerally about and in the direction of a rotational axis 20. The gasturbine engine 10 further comprises a shaft 22 which is rotatable aboutthe rotational axis 20 and which extends longitudinally through the gasturbine engine 10. The shaft 22 drivingly connects the turbine section18 to the compressor section 14.

In operation of the gas turbine engine 10, air 24, which is taken inthrough the air inlet 12 is compressed by the compressor section 14 anddelivered to the combustion section or burner section 16. The burnersection 16 comprises a burner plenum 26, one or more combustion chambers28 extending along a longitudinal axis 35 and at least one burner 30fixed to each combustion chamber 28. The combustion chambers 28 and theburners 30 are located inside the burner plenum 26. The compressed airpassing through the compressor 14 enters a diffuser 32 and is dischargedfrom the diffuser 32 into the burner plenum 26 from where a portion ofthe air enters the burner 30 and is mixed with a gaseous or liquid fuel.The air/fuel mixture is then burned and the combustion gas 34 or workinggas from the combustion is channelled through the combustion chamber 28to the turbine section 18 via a transition duct 17. The combustionsection 16 includes a combustor triple liner assembly 1 according to thepresent technique. The burner 30 and the combustor triple liner assembly1 together form the combustor assembly 100 according to the presenttechnique.

This exemplary gas turbine engine 10 has a cannular combustor sectionarrangement 16, which is constituted by an annular array of combustorcans 19 each having the burner 30 and the combustion chamber 28, thetransition duct 17 has a generally circular inlet that interfaces withthe combustor chamber 28 and an outlet in the form of an annularsegment. An annular array of transition duct outlets form an annulus forchannelling the combustion gases to the turbine 18.

The turbine section 18 comprises a number of blade carrying discs 36attached to the shaft 22. In the present example, two discs 36 eachcarry an annular array of turbine blades 38. However, the number ofblade carrying discs could be different, i.e. only one disc or more thantwo discs. In addition, guiding vanes 40, which are fixed to a stator 42of the gas turbine engine 10, are disposed between the stages of annulararrays of turbine blades 38. Between the exit of the combustion chamber28 and the leading turbine blades 38 inlet guiding vanes 44 are providedand turn the flow of working gas onto the turbine blades 38.

The combustion gas 34 from the combustion chamber 28 enters the turbinesection 18 and drives the turbine blades 38 which in turn rotate theshaft 22. The guiding vanes 40, 44 serve to optimise the angle of thecombustion or working gas 34 on the turbine blades 38.

The turbine section 18 drives the compressor section 14. The compressorsection 14 comprises an axial series of vane stages 46 and rotor bladestages 48. The rotor blade stages 48 comprise a rotor disc supporting anannular array of blades. The compressor section 14 also comprises acasing 50 that surrounds the rotor stages and supports the vane stages48. The guide vane stages include an annular array of radially extendingvanes that are mounted to the casing 50. The vanes are provided topresent gas flow at an optimal angle for the blades at a given engineoperational point. Some of the guide vane stages have variable vanes,where the angle of the vanes, about their own longitudinal axis, can beadjusted for angle according to air flow characteristics that can occurat different engine operations conditions.

The casing 50 defines a radially outer surface 52 of the passage 56 ofthe compressor 14. A radially inner surface 54 of the passage 56 is atleast partly defined by a rotor drum 53 of the rotor which is partlydefined by the annular array of blades 48.

The present technique is described with reference to the above exemplaryturbine engine having a single shaft or spool connecting a single,multi-stage compressor and a single, one or more stage turbine. However,it should be appreciated that the present technique is equallyapplicable to two or three shaft engines and which can be used forindustrial, aero or marine applications. Furthermore, the cannularcombustor section arrangement 16 is also used for exemplary purposes andit should be appreciated that the present technique is equallyapplicable to annular type and can type combustion chambers.

The terms upstream and downstream refer to the flow direction of theflow of cooling air unless otherwise stated. The terms forward andrearward refer to the general flow of cooling air through the burnersection and particularly through the combustor triple liner assembly 1of the present technique. The terms axial, radial and circumferentialare made with reference to the longitudinal axis 35 of the combustionchamber 28, unless otherwise stated.

The basic idea of the invention is to segment the flow-path of thecooling air in such a way that development of cross flows is at leastpartially obviated. By the present technique the cooling air iseffectively used i.e. for example less air is required for cooling andthus more air is available for combustion which in turn increases engineefficiency.

Referring to FIGS. 2 and 3 in combination with FIGS. 4,5 and 6, anexemplary embodiment of the combustor triple liner assembly 1 accordingto the present technique has been described hereinafter. The combustortriple liner assembly 1 is to be integrated or is integrated in theburner section or combustor section 16 of the gas turbine engine 10 ofFIG. 1.

The combustor triple liner assembly 1, hereinafter also referred to asthe assembly 1, as depicted in FIGS. 2 and 3, includes an inner liner60, a middle liner 70, an outer liner 80, a plurality of inner dividers92 and a plurality of outer dividers 93.

The inner liner 60 is a cylinder, or in other words is cylindrical inshape, and has a longitudinal axis that is same as the longitudinal axis35. The combustion chamber 28 is defined in the space defined orcontained within the cylindrical inner liner 60. The inner liner 60 hasan inner surface 61 and an outer surface 62. The inner surface 61 formsthe boundary of the combustion chamber 28 or in other words the innersurface 61 of the inner liner 60 faces the combustion chamber 28 or thelongitudinal axis 35. The outer surface 62 is a surface opposite to theinner surface 61 i.e. the outer surface 62 faces away from thecombustion chamber 28. The inner liner 60 is housed within the middleliner 70.

The middle liner 70 is a cylinder, or in other words is cylindrical inshape, and houses the inner liner 60. The middle liner 70 has an innerside 71 and an outer side 72. The inner side 71 is the surface of themiddle liner 70 facing the inner liner 60 i.e. facing the longitudinalaxis 35. The outer side 72 is the surface of the middle liner 70opposite to the inner side 71 i.e. the outer side 72 faces away from theinner liner 60 and also the longitudinal axis 35. The inner liner 60 andthe middle liner 70 are coaxially arranged about the longitudinal axis35, hereinafter also referred to as the axis 35. The inner liner 60 andthe middle liner 70 are radially spaced apart about the axis 35. Aradial direction 5 about the axis 35 is schematically depicted in FIG.2. Thus the inner liner 60 and the middle liner 70 create a spacebetween them, i.e. between the outer surface 62 of the inner liner 60and the inner surface 71 of the middle liner 70. The space is an innerannular flow-path 2. As is depicted in FIGS. 2 and 3, the inner liner 60and the middle liner 70 extend longitudinally so as to cover or enwrapthe combustion chamber 28. The middle liner 70 having the inner liner 60housed therewithin is in turn housed within the outer liner 80.

The outer liner 80 is a cylinder, or in other words is cylindrical inshape, and houses the middle liner 70. The outer liner 80 has an innerside 81 and an outer side 82. The inner side 81 is the surface of theouter liner 80 facing the middle liner 70 i.e. facing the longitudinalaxis 35. The outer side 82 is the surface of the outer liner 80 oppositeto the inner side 81 i.e. the outer side 82 faces away from the middleliner 70 and also the longitudinal axis 35. The middle liner 70 and theouter liner 80 are coaxially arranged about the longitudinal axis 35.The middle liner 70 and the outer liner 80 are radially spaced apartabout the axis 35 i.e. in the direction 5. Thus the middle liner 70 andthe outer liner 80 create a space between them, i.e. between the outersurface 72 of the middle liner 70 and the inner surface 81 of the outerliner 80. The space is an outer annular flow-path 3. As is depicted inFIGS. 2 and 3, the middle liner 70 and the outer liner 80 extendlongitudinally so as to cover or enwrap the combustion chamber 28.

Thus, as depicted in FIGS. 2 and 3 the inner liner 60 is housed in themiddle liner 70 and the middle liner 70 is in turn housed in the outerliner 80. The inner liner 60, the middle liner 70 and the outer liner 80are coaxially aligned about the longitudinal axis 35 and are radiallyseparated with respect to the longitudinal axis 35 to create the innerannular flow-path 2 between the inner liner 60 and the middle liner 70,and to create the outer annular flow-path 3 between the middle liner 70and the outer liner 80. Furthermore, the inner liner 60, the middleliner 70 and the outer liner 80 extend longitudinally so as to cover orenwrap the entire stretch of the combustion chamber 28.

As depicted in FIGS. 2 and 3, the inner dividers 92 are seriallyarranged longitudinally, i.e. one inner divider 92 is separated fromanother inner divider 92 along the longitudinal axis 35. The innerdividers 92 are positioned within the inner annular flow-path 2. Each ofthe inner dividers 92 is a flat annular disc. The flat sides, i.e. thefaces of the annular disc shaped inner dividers 92 are alignedperpendicular to the longitudinal axis 35, or in other words a radialdirection of the annular disc shaped inner dividers 92 is alignedperpendicular to the longitudinal axis 35. Each inner divider 92 extendsradially about the longitudinal axis 35 between the inner liner 60 andthe middle liner 70 thereby dividing the inner annular flow-path 2 intoa plurality of inner compartments 201,202,203. The two circumferentialedges of each of the annular disc shaped inner dividers 92 are radiallyapart from each other by same distance as the radial separation betweenthe outer surface 62 of the inner liner 60 and the inner surface 71 ofthe middle liner 70. In other words, an outer circumferential edge ofthe annular disc shaped inner divider 92 is in physical contact with theinner surface 71 of the middle liner 70 whereas an inner circumferentialedge of the annular disc shaped inner divider 92 is in physical contactwith the outer surface 62 of the inner liner 60, such cooling air 7flowing into the inner annular flow-path 2 when encounters one of theinner dividers 92 cannot flow across the inner divider 92 unless a holeor an opening is provided through the inner divider 92 for flow of thecooling air 7. To explain further, each inner compartment 201,202,203between any two of the inner dividers 92 is hermetically sealed by theinner dividers 92, the outer surface 62 of the inner liner 60, and theinner surface 71 of the middle liner 70 unless a hole or an opening isprovided through the inner divider 92, or the inner liner 60, or themiddle liner 70 to allow the cooling air 7 to flow out of the innercompartment 201,202,203.

As depicted in FIGS. 2 and 3, the outer dividers 93 are seriallyarranged longitudinally, i.e. one outer divider 93 is separated fromanother outer divider 93 along the longitudinal axis 35. The outerdividers 93 are positioned within the outer annular flow-path 3. Each ofthe outer dividers 93 is a flat annular disc. The flat sides, i.e. thefaces of the annular disc shaped outer dividers 93 are alignedperpendicular to the longitudinal axis 35, or in other words a radialdirection of the annular disc shaped outer dividers 93 is alignedperpendicular to the longitudinal axis 35. Each outer divider 93 extendsradially about the longitudinal axis 35 between the middle liner 70 andthe outer liner 80 thereby dividing the outer annular flow-path 3 into aplurality of outer compartments 301,302,303. The two circumferentialedges of each of the annular disc shaped outer dividers 93 are radiallyapart from each other by same distance as the radial separation betweenthe outer surface 72 of the middle liner 70 and the inner surface 81 ofthe outer liner 80. In other words, an outer circumferential edge of theannular disc shaped outer divider 93 is in physical contact with theinner surface 81 of the outer liner 80 whereas an inner circumferentialedge of the annular disc shaped outer divider 93 is in physical contactwith the outer surface 72 of the middle liner 70, such cooling air 7flowing into the outer annular flow-path 3 when encounters one of theouter dividers 93 cannot flow across the outer divider 93 unless a holeor an opening is provided through the outer divider 93 for flow of thecooling air 7. To explain further, each outer compartment 301,302,303between any two of the outer dividers 93 is hermetically sealed by theouter dividers 93, the outer surface 72 of the middle liner 70, and theinner surface 81 of the outer liner 80 unless a hole or an opening isprovided through the outer divider 93, or the middle liner 70, or theouter liner 80 to allow the cooling air 7 to flow out of the outercompartment 301,302,303.

The inner dividers 92 and the outer dividers 93 may be friction fittedor brazed or may be physically contacted in any other way with the innerliner 60 and middle liner 70, and with the middle liner 70 and the outerliner 80, respectively such that the corresponding physical contacts areair-tight.

As shown in FIG. 3, the outer dividers 93 also divide or segment themiddle liner 70 into a plurality of middle liner sections 701,702,703corresponding to each outer compartment 301,302,303 i.e. each of outercompartment 301,302,303 includes one middle liner section 701,702,703,for example as depicted in the example of FIG. 3 the outer compartment301 includes the middle liner section 701, the outer compartment 302includes the middle liner section 702, and the outer compartment 303includes the middle liner section 703.

The middle liner section 701,702,703, of each outer compartment301,302,303, includes a plurality of impingement holes 75. In anembodiment of the combustor triple liner assembly 1, the impingementholes 75 are positioned in form of an array that extendscircumferentially and axially in the middle liner section 701,702,703.The impingement holes 75 of each outer compartment 301,302,303, fluidlyconnect that outer compartment 301,302,303, to one corresponding innercompartment 201,202,203, and the corresponding inner compartment201,202,203, is fluidly connected to one corresponding downstream outercompartment 301,302,303, through at least one opening 77 in the middleliner 70 of the downstream outer compartment 301,302,303, such thatcooling air entering the outer annular flow-path 3 flows from the outercompartment 301,302,303, through the impingement holes 75 of the outercompartment 301,302,303, into the corresponding inner compartment201,202,203, and therefrom through the opening 77 into the correspondingdownstream outer compartment 301,302,303. The scheme of flow of thecooling air 7 has been explained in further details with respect to FIG.7.

As shown in FIG. 7, the cooling air 7 enters in the outer annularflow-path 3 in a direction depicted by arrow marked with referencenumeral 91. The cooling air 7 is at this stage in one of the outercompartments 301,302,303, and in the example of FIG. 7, the cooling air7 at this stage is in the outer compartment 301. The middle linersection 701 of the outer compartment 301 has the impingement holes 75.The cooling air 7 flows through the impingement holes 75 of the middleliner section 701 of the outer compartment 301 into the correspondinginner compartment 201 in form of impingement jets 76 ejected from theimpingement holes 75 to impact the outer surface 62 of the inner liner60. Thereafter the cooling air 7 flows from the corresponding innercompartment 201 through the opening 77 into the corresponding downstreamouter compartment 302. Thus, the cooling air 7 at this stage is in theouter compartment 302. The middle liner section 702 of the outercompartment 302 has the impingement holes 75. The cooling air 7 flowsthrough the impingement holes 75 of the middle liner section 702 of theouter compartment 302 into the corresponding inner compartment 202 inform of impingement jets 76 ejected from the impingement holes 75 toimpact the outer surface 62 of the inner liner 60. Thereafter thecooling air 7 flows from the corresponding inner compartment 202 throughthe opening 77 into the corresponding downstream outer compartment 303.The flow of the cooling air 7 continues according to this scheme in ageneral direction 9 of the flow of the cooling air 7. The cooling 7flowing according to the aforementioned scheme reaches a last outercompartment, say the outer compartment 303. The middle liner section 703of the outer compartment 303 has the impingement holes 75. The coolingair 7 flows through the impingement holes 75 of the middle liner section703 of the outer compartment 303 into the corresponding innercompartment 203, i.e. the last inner compartment 203, in form ofimpingement jets 76 ejected from the impingement holes 75 to impact theouter surface 62 of the inner liner 60. Thereafter the cooling air 7flows from the corresponding inner compartment 203 into one or more ofthe burners 30 to mix with fuel and burn inside the combustion chamber28 as depicted by the arrow marked with reference numeral 99 in FIG. 7,or the cooling air 7 may flow to some other structure (not shown).

Hereinafter additional embodiments of the combustor triple linerassembly 1 have been explained.

As shown in FIG. 4 the inner liner 60 may be a continuous surfacewithout any perforations. Alternatively, as shown in FIG. 5 in anembodiment of the combustor triple liner assembly 1, the inner liner 60includes a plurality of film cooling holes 66. The film cooling holes 66allow a part of the cooling air 7 from the inner compartments201,202,203 where the film cooling holes 66 are located, to enter thecombustion chamber 28. FIG. 7 depicts flow of the part of cooling air 7through the film cooling holes 66 by arrows marked with referencenumeral 67. Furthermore, as also schematically depicted in FIG. 5, inanother embodiment of the combustor triple liner assembly 1, the innerliner 60 includes at least one dilution hole 68. A size, for example 10mm to 30 mm and advantageously 20 mm in the diameter, of the dilutionholes 68 is larger than a size, for example 0.5 mm to 2 mm andadvantageously 1 mm in the diameter, of the film cooling holes 66. Thedilution holes 68 allows a part of the cooling air 7 from the innercompartments 201,202,203 where the dilution hole 68 is located, to enterthe combustion chamber 28. FIG. 7 also depicts flow of the part ofcooling air 7 through the dilution holes 68 by arrows marked withreference numeral 69.

As shown in FIGS. 3 and 6, in an exemplary embodiment of the combustortriple liner assembly 1, the outer dividers 93 include one or moreby-pass holes 94. The by-pass holes 94 allow a part of the cooling air 7to flow from the outer compartment 301,302,303 upstream, with respect tothe general direction 9 of the flow of the cooling air 7, of the outerdivider 93 into the outer compartment 301,302,303 downstream of theouter divider 93, without flowing through any inner compartment201,202,203. A plurality of the by-pass holes 94 may becircumferentially arranged about the longitudinal axis 35. FIG. 7 alsodepicts flow of the part of cooling air 7 through the by-pass holes 94by arrows marked with reference numeral 95.

FIGS. 8, 9, 10 and 11 schematically illustrate exploded views ofdifferent exemplary embodiment of the combustor triple liner assembly 1.

As schematically depicted in FIG. 8, in an embodiment of the combustortriple liner assembly 1, the outer dividers 93 are integrally formedwith the outer liner 80, i.e. the outer dividers 93 are formed as onepart extensions of the outer liner 80. The outer dividers 93 projectout, i.e. in radially inward direction with respect to the axis 35, fromthe inner surface 81 of the outer liner 80. In this embodiment of thecombustor triple liner assembly 1, the inner dividers 92 are integrallyformed with the middle liner 70, i.e. the inner dividers 92 are formedas one part extensions of the middle liner 70. The inner dividers 92project out, i.e. in radially inward direction with respect to the axis35, from the inner surface 71 of the middle liner 70. Thus the combustortriple liner assembly 1 according to this embodiment has only threeparts or components i.e. the inner liner 60, the middle liner 70 withthe integrally formed inner dividers 92, and the outer liner 80 with theintegrally formed outer dividers 93. When assembled, the middle liner 70is sandwiched between the inner liner 60 and the outer liner 80 suchthat the inner dividers 92 of the middle liner 70 physically contact theouter surface 62 of the inner liner 60 and the outer dividers 93 of theouter liner 80 physically contact the outer surface 72 of the middleliner 70.

As schematically depicted in FIG. 9, in another embodiment of thecombustor triple liner assembly 1, the outer dividers 93 are integrallyformed with the outer liner 80, i.e. the outer dividers 93 are formed asone part extensions of the outer liner 80. The outer dividers 93 projectout, i.e. in radially inward direction with respect to the axis 35, fromthe inner surface 81 of the outer liner 80. In this embodiment of thecombustor triple liner assembly 1, the inner dividers 92 are integrallyformed with the inner liner 60, i.e. the inner dividers 92 are formed asone part extensions of the inner liner 60. The inner dividers 92 projectout, i.e. in radially outward direction with respect to the axis 35,from the outer surface 62 of the inner liner 60. Thus the combustortriple liner assembly 1 according to this embodiment has only threeparts or components i.e. the inner liner 60 with the integrally formedinner dividers 92, the middle liner 70, and the outer liner 80 with theintegrally formed outer dividers 93. When assembled, the middle liner 70is sandwiched between the inner liner 60 and the outer liner 80 suchthat the inner dividers 92 of the inner liner 60 physically contact theinner surface 71 of the middle liner 70 and the outer dividers 93 of theouter liner 80 physically contact the outer surface 72 of the middleliner 70.

As schematically depicted in FIG. 10, in another embodiment of thecombustor triple liner assembly 1, the outer dividers 93 are integrallyformed with the middle liner 70, i.e. the outer dividers 93 are formedas one part extensions of the middle liner 70. The outer dividers 93project out, i.e. in radially outward direction with respect to the axis35, from the outer surface 72 of the middle liner 70. In this embodimentof the combustor triple liner assembly 1, the inner dividers 92 areintegrally formed with the inner liner 60, i.e. the inner dividers 92are formed as one part extensions of the inner liner 60. The innerdividers 92 project out, i.e. in radially outward direction with respectto the axis 35, from the outer surface 62 of the inner liner 60. Thusthe combustor triple liner assembly 1 according to this embodiment hasonly three parts or components i.e. the inner liner 60 with theintegrally formed inner dividers 92, the middle liner 70 with theintegrally formed outer dividers 93, and the outer liner 80. Whenassembled, the middle liner 70 is sandwiched between the inner liner 60and the outer liner 80 such that the inner dividers 92 of the innerliner 60 physically contact the inner surface 71 of the middle liner 70and the outer dividers 93 of the middle liner 70 physically contact theinner surface 81 of the outer liner 80.

As schematically depicted in FIG. 11, in a further embodiment of thecombustor triple liner assembly 1, the outer dividers 93 and the innerdividers 92 are integrally formed with the middle liner 70, i.e. theinner dividers 92 and the outer dividers 93 are formed as one partextensions of the middle liner 70. The inner dividers 92 project out,i.e. in radially inward direction with respect to the axis 35, from theinner surface 71 of the middle liner 70 whereas the outer dividers 93project out, i.e. in radially outward direction with respect to the axis35, of the outer surface 72 of the middle liner 70. Thus the combustortriple liner assembly 1 according to this embodiment has only threeparts or components i.e. the inner liner 60, the middle liner 70 withthe integrally formed inner and outer dividers 92,93 and the outer liner80. When assembled the middle liner 70 is sandwiched between the innerliner 60 and the outer liner 80 so that the inner dividers 92 of themiddle liner 70 physically contact the outer surface 62 of the innerliner 60 and the outer dividers 93 of the middle liner 70 physicallycontact the inner surface 81 of the outer liner 80.

While the present technique has been described in detail with referenceto certain embodiments, it should be appreciated that the presenttechnique is not limited to those precise embodiments. Rather, in viewof the present disclosure which describes exemplary modes for practicingthe invention, many modifications and variations would presentthemselves, to those skilled in the art without departing from the scopeand spirit of this invention. The scope of the invention is, therefore,indicated by the following claims rather than by the foregoingdescription. All changes, modifications, and variations coming withinthe meaning and range of equivalency of the claims are to be consideredwithin their scope.

1. A combustor triple liner assembly for a gas turbine engine, thecombustor triple liner assembly comprising: an inner liner having alongitudinal axis and defining a combustion chamber, a middle linerhousing the inner liner, an outer liner housing the middle liner and theinner liner, wherein the inner liner, the middle liner and the outerliner are coaxially aligned cylinders and are radially separated tocreate an inner annular flow-path between the inner liner and the middleliner, and to create an outer annular flow-path between the middle linerand the outer liner, a plurality of inner dividers serially arrangedlongitudinally within the inner annular flow-path, wherein each of theinner dividers extends radially between the inner liner and the middleliner dividing the inner annular flow-path into a plurality of innercompartments, a plurality of outer dividers serially arrangedlongitudinally within the outer annular flow-path, wherein each of theouter dividers extends radially between the middle liner and the outerliner dividing the outer annular flow-path into a plurality of outercompartments and dividing the middle liner into a plurality of middleliner sections corresponding to each outer compartment, wherein themiddle liner section of each outer compartment comprises a plurality ofimpingement holes fluidly connecting the outer compartment to onecorresponding inner compartment and wherein the corresponding innercompartment is fluidly connected to one corresponding downstream outercompartment through at least one opening in the middle liner, such thatcooling air entering the outer annular flow-path flows from the outercompartment through the impingement holes of the outer compartment tothe corresponding inner compartment and therefrom through the opening tothe corresponding downstream outer compartment.
 2. The combustor tripleliner assembly according to claim 1, wherein the inner liner comprises aplurality of film cooling holes adapted to allow a part of the coolingair from at least one of the inner compartments to enter the combustionchamber and to provide film cooling of an inner surface of the innerliner.
 3. The combustor triple liner assembly according to claim 1,wherein the inner liner comprises at least one dilution hole adapted toallow a part of the cooling air from at least one of the innercompartments to enter the combustion chamber to dilute the combustiongases in the combustion chamber
 4. The combustor triple liner assemblyaccording to claim 1, wherein the impingement holes are located in themiddle liner section of each outer compartment as an array extendingcircumferentially and axially in the middle liner section.
 5. Thecombustor triple liner assembly according to claim 1, wherein at leastone of the outer dividers comprises one or more by-pass holes configuredto allow a part of the cooling air to flow from the outer compartmentupstream of the outer divider to the outer compartment downstream of theouter divider.
 6. The combustor triple liner assembly according to claim1, wherein the outer dividers are integrally formed with the middleliner.
 7. The combustor triple liner assembly according to claim 6,wherein the inner dividers are integrally formed with the middle liner.8. The combustor triple liner assembly according to claim 6, wherein theinner dividers are integrally formed with the inner liner.
 9. Thecombustor triple liner assembly according to claim 1, wherein the outerdividers are integrally formed with the outer liner.
 10. The combustortriple liner assembly according to claim 9, wherein the inner dividersare integrally formed with the middle liner.
 11. The combustor tripleliner assembly according to claim 9, wherein the inner dividers areintegrally formed with the inner liner.
 12. A combustor assemblycomprising: a burner and a combustor triple liner assembly, wherein thecombustor triple liner assembly is according to claim
 1. 13. A gasturbine engine comprising: a combustor triple liner assembly, whereinthe combustor triple liner assembly is according to claim 1.